Controlled synthesis, immobilization and chiral recognition of carboxylic acid functionalized cellulose...

Traditional cellulose-based chiral stationary phases (CSPs) are prepared by physically coating cellulose derivatives onto substrates and only compatible with a very limited range of solvents as the mobile phase. Therefore, chemical immobilization of cellulose derivatives onto silica gel has been efficiently applied to improve the solvent compatibility of cellulose-based CSPs. Here we developed a novel approach to homogeneously modifying cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC). A series of carboxylic acid functionalized CDMPCs (CC-Xs) with controlled amounts and randomly distributed carboxylic acid groups was synthesized. CC-Xs were effectively immobilized onto amine-modified silica gel to afford immobilized CSPs. Compared to coated-type CSPs, immobilized CSPs significantly improved the solvent compatibility while maintaining similar chiral recognition abilities, but the introduction of excessive functional groups led to a deteriorated performance for columns. Moreover, a commercial drug, atenolol, was also sufficiently separated on the immobilized CSPs.